“Will being under ‘Siege’ affect workers?”

Yes, but not directly – actually, being under siege affects the complete population, because it quite obviously lowers a planet’s “security level”, which lowers the planet’s happiness, which in turns causes a bit of inefficiency.

“Will workers from races more suited for a certain job automaticly go too them?”

Although that would be more realistic, no, they won’t – too many computations.

Will workers from races more suited for a certain job automaticly go too them?